Water-tube boiler.



J. E.'THORNYCROFT. w'ATl-:n TUBE BolLER.

(Application med. May 23. 1900.)

No. 670,976. Patented Apr. 2, |90L (llol Mloldel.) 4 Sheets-Sheet l.

nms Pasks co., wom-uma. wAsHmaYoN. n. c4.

No. A$70,976. Patented Apr. 2, 190i.

I J. E. THORNYCR-UFT.

WATER TUBE BOILER.

(Application le May 23, 1900., (No Model.) 4 Sheets-Sheet 3.

tu: u

cams Freins co, Nom-umu., wnsmunmn. n4 c x NIL 670,976.

(No Model.)

J. E. THORNYCRUFT WATER Tune Bones.

(Appncman med my 2a, 1900.,

Patented Apr. 2; 190|.

4 Shaetr-Sheat 4.

Enron.

JOHN EDVARD THORNYCROFT, OF CHISWICK, ENGLAND.

WATER-TUBE BOILER.

.SLE'EGFIUATION forming part of Letters Patent No. 670,976, dated April 2, 1901.

Application filed May 23, 1900.

To (LN, iff/1,071?, it 717101/ concern:

Be it k nmvn that I, JOHN EDWARD THORNY- CRoFT, a subject of the Queen of Great Britain and Ireland, residing at Hometield, Chis- \viok, in the county of Middlesex` England, have invented Improvements in Vater-'lluhe Boilers, of which the following is a specification.

This invention has reference to water-tu be boilers of the kind wherein water is caused to pass through a n um berof pairs of water-tubes that are arranged to extend from front to back of the boiler over a Atire grate or grates, and the two tubes of each pair are inclined toward one another, as seen from either side of the boiler, and have their converging ends connected together through a junction-box and their diverging ends connected at different levels to one or more water-supply boxes or headers, so that water can flow upward simultaneously through all the pairs of tubes.

One object of the present invention is to enable water after dowing through the pairs of tubes and becoming thereby heated to im1nediately reenter the tubes without loss of time and heat, so that it can be quickly converted into steam and so enable a boiler of the kind referred to having a high evaporative efficiency to be obtained.

Afurther Objectis to enable the upper steam and water vessel to be connected to the upper part of the Water-supply box or chamber in such a manner as to enable steam to readily low from the latter to the former and water from the former to the latter through connections so arranged as not to unduly weaken the said steam and Water vessel.

Vith these and other objects in View the invention consists in certain improved constructions and arrangements of parts of boilers of the kind referred to, as will be hereinafter fully described, and pointed out in the claims hereunto appended.

In the accompanying illustrative drawings, which form part of this specification, Figure l is a longitudinal section on the line A A of Fig. 2; and Fig. 2 is a part rear elevation and a part cross-section on the line B B of Fig. l, showing a boiler of the kind referred to con struoted according to this invention and suitable for marine use. Fig. 3 is a part section on the line C C ot Fig. l. Fig. 4L is a front Serial No, 17,640. (No modell view ot' one of the pairs of water-tnbes. Fig. 5 is a sectional plan view showing ainodication. Fig. 6 is a similar view to Fig. l, showing a modified construction ol boiler suitable for land use.

l and 2 are the two inclined water-tubes composing each pair of waterftubes extending from front to rear of the boiler above the tiregrate 3. The diverging ends at and 5 ol` each pair ot' water-tubes l and 2, respectively, are fixed in a common tube-plate 6, that forms one wall of a vertically-arranged water-box G, the interior of which is common to and is in free and direct communication with the interiors of all the water-tn bes, so that the diverg- -ing ends 4l and 5 of the several tubes are in direct a nd free communication with each other through the said waterbox. 'Fh is water-box in the arrangement shown in Figs. l to 4, inclusive, Which show the preferred construction of boiler, is arranged at the rear of the combustionchamber, is closed at the bottom, and is directly connected by a n u m ber of forwardly-extending tubes 7a to the lower part of a comparatively large transversely-arran ged cylindrical steam and water vessel 8, (hereinafter called the steamdru1n,) arranged at the front of the boiler above the converging ends of the pairs of water-tubes l and2. Other tubes'connect the steam and water vessel 8 with the upper part of the watenbox 6 and convey steam from the latter to the former. The other or rear dat wall 6" of the Water-box is connected to the front Wall oat thereof by stays 9, (preferably made tubular,) and is formed with holes l0, that are arranged opposite the diverging ends a and 5 of the water-tu bes l and 2 and are normally closed by suitable removable stoppers ll. 'lhe converging ends of each pair of Water-tubes l and 2 are connected by a common junction-box l2, that is also formed With holes provided with Stoppers 13, arranged opposite the adjacent ends of the tubes. 13 the tubes can be readily examined and cleaned. The connected Water-tubes l and 2 and junction-boxes l2 arearranged in'acombustion-chamber 14 above the tire-grate 3 (or grates) and below a chimney or uptake l5, and are inclosed in a suitable casing 16, the front and back of which are provided, as usual, with doors for gaining access to the tube ends.

By removing the stoppers ll andl TOO By the construction described water can flow from the water-box 6 to the lower ends 4 of all the pairs of Water-tubes 1 and 2 simultaneously, and water and steam can flow from the upper ends 5 of the pairs of tubes into the water-box 6, wherein the steamY will rise to the top of the box and pass by the upper connecting-tubes 7 to the steamdrum 8, while the water can at once renter the lowerends 4 of the .water-tubes without the loss of time and heat that usually7 takes place when such water has 'first to pass up to the steam-drum 8 and thence back through an external or other down take pipe or pipes to a lower water vessel, from which it Hows through a number ot' vertical headers to the lower ends of the pairs of water-tubes, as in some earlier constructions ot' water-tube boilers ofthe type referred to. Water that enters the steamdrum 8 with the steam through the tubes 7 can return to the water-box through the lower connecting-tubes 7a. Also by arranging the steam-drum 8 at the front of the boiler and the water-box 6 at the back thereof, as described, a comparatively large number of tubes 7 7 can be used for connecting the two. Consequently the holes in the lower part ofthe steam -druin can be made comparatively small and arranged in a zigzag manner, so that the steam-drum will not be weakened to such an extent as when the water-box is located directly below it and communicates with its interior through a single row of comparatively large holes,as in some former constructions of boilers of the type referred to.

The junction-box. 12, connecting the converging ends of each pair of water-tubes1 and 2, is inclined upward from the part where the lower tube 1 is connected to it to the part where the u pper tube 2 is connected to it,Fig. 4, in order that the said tubes may bearranged closer together, as seen in plan, than would be possible if the junction-box were arranged horizontally. By this arrangement. the inner walls of the tubes of each pair can be brought into approximately the same vertical plane. Also the holes in the tube-plate 6, in which the ends 4 and 5 ot' the tubes 1 and 2 are xed, are for a like purpose and as shown in Fig. 2 correspondingly arranged, so that, as seen in plan, the tubes 1 and 2 of each pair are parallel and apparently touching one another, or nearly so. By this means when all the water-tubes are in place within the combustion-chamber 14 the hot gases will have to take a zigzag course between the tubes while passing to the chimney, no vertical spaces of appreciable width being left between the tubes through which hot gases can ascend without being brought into intimate and effective contact with the tubes. One or more baffle-plates or devices 17 may be arranged on or above or between the uppermost watertubes to assist the effective distribution of the hot gases among the tubes.

The water-tubes 1 and 2 are or may advantageously be slightly curved in the direction ot' their length, the curvature being such that the lower tube 1 of each pair is convex toward the fire and the Lipper tube 2 of each pair is concave on the side toward the fire, as described in the specification of another application forLetters Patent filed by me, dated November 27, 18699, Serial No. 738,316. this arrangement I obviate the injurious eitects of the unequal expansion of the tubes brought about by reason of the lower tube of each pair being exposed to greater heat. than the lupper tube viz., the tendency as the temperature rises of the upper tube of the pair to be withdrawn from the tube-plate 6""L and junction-box 12, to which it is connected, the tendency of the lower tube of the pair to be forced into the said tube-plate and junction-box, whereby leaky joints are produced, and the tendency of the tubes to lift the junction-boxes by reason of unequal expansion of the tubes 1 and 2. The curving of the tubes also facilitates the escape ot' steam therefrom and so minimizesliability of overheating of the tubes. Furthermore, the curving of the tubes also enables their rear ends to be arranged at right angles to the tube-plate 6, in which they can 'consequen tly be readily expanded and secured and facilitates the withdrawal of the tubes.

The water-box 6 may, as shown in Fig. 1, conveniently be formed of two approximately rectangular dished plates 6a 6b, iixed at a suitable distance apart bythe stays 9 and secured by their flanged edges to and within an outer or peripheral plate 6c of approximately rectangular shape in end View. The water-box is or may be provided with a blow-off cock, so that all the pairs of water-tubes 1 and 2 can be simultaneously and quickly emptied of water when desired.

Instead of a single wide water-box constructed and arranged as described and common to all the pairs of connected water-tubes two or more narrower water-boxes may in some cases be used, arranged side by side. This modiedcon struction will be understood from Fig. 2 if it be assumed that the dotted line A A shows the division between adjacent water-boxes.

A water-box 6, such as hereinbefore described and having no internal divisionplates, may in some cases, as shown in Fig. 6, be arranged at the front of the boiler below the steam-drum 8, to which it is suitably connected, as bytwo rows of tubes 7b 7, the converging ends of the pairs of water-tubes 1 and 2 being then at the rear of the boiler. This construction of boiler, which in other respects is like that hereinbetore described with reference to Figs. 1 to 4, inclusive, is more particularly suitable for land and other use where it is not desired to use it back to back with another boiler andwhere the pairs of water-tubes can therefore be readily withdrawn from the back of the boiler.

As will be obvious, various changes in the construction and arrangement of the boiler IIO may be made without departing from the essential features ot' the invention. The invention is not, therefore, to be considered as limited to the precise constructions described and shown, but as embracing all changes and variations which Fall within its spirit and scope.

What l claim isl. In a steam-boiler, the,combination of a plurality of independent pairs of water-t ubes, the two tubes of each pair being arranged in diiferent vertical planes and connected together at one end by a junction-box and having their other ends located at diiferent levels` au upwardly-extending water-box having one of its sides connected to the ends of the tubes that are at different levels, and an up per steam and water vessel connected to said water-box, substantially as described.

z5. In a steam-boiler, the combination of a plurality of independent pairs of inclined watertubes, the two tubes of each pair being inclined toward one anothe and arranged with their inner walls in approximately the same vertical plane, and having their converging ends connected together by a junction'box, a water-box closed at the bottom and to one side otwhich the diverging ends of the pairs of water-tu bes are connected at different levels, and an upper steam and Water vessel connected to said water-box, substantially as described.

In a steam-boiler, the combination of a plurality of independent pairs of water-tubes, the two tubes of each pair being arranged in ditferent vertical planes, connected together at. one end by a junction-box and having their other ends located at different levels, an upwardlyfextending water-box having one of its sides connected to the ends of the tubes that are at different levels and its interior undi vided and in direct free and open communication with the interior of said Water-tubes so that water can flow direct from the outlet ends of said pairs of tubes to the inlet ends thereof through said water-box, and an upper steam and water vessel connected to said water-box, substantially as described.

4. In a steam-boiler, the combination of an upwardly-extending water-box, pairs of oppositelyinclined water-tubes connected at one end to and extending from one side of said water-box and connected at their other ends by junction-boxes, and an upper steam and wat-er vessel connected to said water-box and located above said junction-boxes, substantially as described.

5. In a steam-boiler, the combination of an upwardly-extending water-box arranged at the rear of the boiler, a plurality of pairs of oppositely -inclined watertubes extending from front to back ot the boiler and having their direi-ging ends connected at diit'erent levels to the front wall of said water-box and their converging ends connected together by junction-boxes, and an upper steam and water vessel connected to the upper part of said water-box, substantially as described.

(5. ln a steam-boiler, the combination of a plurality of pairs ot water-tubes, one of the tubes of each pair being inclined upward and the other downward, the tubes of each pair having their axes in parallel vertical planes and arranged to cross and be arranged in close proximity to the tubes of laterally-adjacent pairs of tubes, means For supplying water to the lower ends ot' said pairs of tubes, and an upper steam and water drum in communication with the upper ends ot said water-tn bes, substantially described.

T. In a steam-boi ler, the combination of one or more water-boxes, water-tu bes tixed to and extending from one side ot' said water box or boxes, said tubes being arranged in Vertical rows with the axes of the tubesin each row in the saine vertical plane, the tubes in each alternate row being inclined upward and those in the intermediate rows downward, and the tubes in each row crossing and being arranged in close proximity to the tubes in adjacent rows, junctionboxes each connecting the adjacent converging ends ot' two tubes together so as to t'orm a connected pair of tubes, and an upper steam and water vessel connected to said water-box, substantially as described.

8. In a steam-boiler, the combination of a plurality ot' pairs of water-tubes, the tubes of each pair vbeing inclined to each other and connected together at their converging ends and each curved in the direction of its length, a water-box having a free and undivided interior so that the diverging ends of all the pairs of tubes connected to said box are in direct and free communication with each other through said water-box, and an upper steam and water vessel connected to said box.

9. A steam boiler comprising a furnacechamber, an upwardly-extending water-box arranged at the rear of the boiler, a plurality of pairs of oppositely-inclined Watertubes connected at their diverging ends to the front Wall of said water-box and extending over the fire-box toward the front of said boiler, the two tubes of each pair being arranged in different vertical planes and connected together at their converging ends by junction-boxes, an upper steam and water vessel connected to said water-box, an uptake located above said water-tubes, and a casing inclosing said water-tubes, substantially as described.

l0. A steatn-boiler comprising a furnace chamber, an upwardly-extending water-box arranged at the rear of the boiler, a plurality of pairs ot' oppositely-inclined water-tubes connected at their diverging ends to the front wall of said water-box, extending over the tire-box toward the front of said boiler and connected together at their converging ends by junction-boxes, an upper steam and Water vessel arranged transversely at the front ot the boiler, a plurality of tubes located above IOO IIO

said Water-tubes and connecting the upper part of said wateibox to said steam and water vessel, an uptake located above said Water and connecting tubes, and a casing in# closing said water-tubes, substantially as described.

11. A steam-boiler comprising a plurality of pairs of Water-tubes extending from front to back of the boiler and arranged one above the other in laterally-adjacent Vertical rows, the tubes of each pair being inclined to'each other and to the horizontal and having their axes in parallel vertical planes, a Water-box closed at the bottom, located at the rear of the boiler and to the front side of which the diverging ends of said'Water-tubes are fixed, junction boXes connecting the converging ends of said pairs of tubes and arranged one above the other in vertical rows at' the front of the boiler and each inclined to the planes containing the axes of the tubes, an upper fransversely-arranged steam and Water vessel locafed at lthe front of the boiler and connected to the upper portion of said Water-box, a furnace-chamber arranged below said Water-tubes, a casing surrounding said watertnbes, and a chimney or uptake located above said Water-tubes, substantially as described.

12. A steam-boiler comprising a flat-sided and stayed vertical water-box located at the rear of the boiler and having a free undivided interior, the rear wall of said Water-box being formed with holes normally closed by removable stoppers, pairs of oppositelyinclined and curved Water-tubes 1 and 2 having their diverging ends fixed to the front side of said water-boX and arranged in dii-ferent vertical planes, inclined junction-boxes with removable stoppers connecting the converging ends of said Water tubes, an upper lrransverse steam and water vessel located at the front of said boiler, rows of tubes arranged above the pairs of Water-tu bes and connecting the lower portion of said steam and Water vessel to the upper portion of said water-box, a furnacechamber located below said water-tubes, a chimney located above the Waterand connecting tubes, and a casing inclosing said watertnbes, substantially as described.

Signed at 77 Cornhill, in the city of London, England, this 7th day of May, 1900.

JOHN EDWARD THORNYCROFT.

Witnesses:

EDMUND S. SNEWIN, WM. O. BROWN. 

